This invention relates to an improvement in a manipulator for a laser knife which uses an optical fiber as a light conducting path.
Laser beams are monochromatic and are excellent in directivity. When a laser beam is focused at a minute point, great energy can be locally obtained. Therefore, laser beams are utilized as laser knifes in the field of medical treatment, and especially when a limited part of the body is subjected to such medical treatment or surgical operation, the use of the laser knife is quite effective.
With a laser knife, a laser beam from a laser oscillating section is applied to that part of the body which is to be subjected to the medical treatment or surgical operation. In this operation, it is required that the laser beam be correctly applied to an extremely small target. In order to meet this requirement, an optical fiber of small weight and excellent flexibility is frequently used as the light conducting path.
In most laser knife manipulators using optical fibers as light conducting paths, the laser beam is applied to the part to be irradiated, with the cover 2 of the optical fiber 1 gripped directly, as shown in FIG. 1, which is an explanatory diagram of the front end portion of a manipulator. Accordingly, the optical fiber 1 is liable to bend during irradiation, as a result of which it is impossible to correctly apply the laser beam to the body part to be irradiated, and the temperature of the manipulator is increased by the reflected light.
In order to overcome these drawbacks, a laser knife manipulator has been proposed in the art, in which, as shown in FIG. 2, the front end portion of the optical fiber 1 is inserted into a hand piece 3 which is made of a straight pipe of metal or synthetic resin. However, this conventional manipulator still suffers from drawbacks in that it is difficult to apply the laser beam in directions other than the axial direction of the hand piece 3; i.e., sometimes the target cannot be lined up with the hand piece and irradiated with the laser beam, with the result that the range of application of the device in medical treatments or surgical operations is limited.